The Barbarian’s Primary use as a mastery is to supplement high risk, high reward, weapon based play-style. 
For DPH, there would be a two-handed weapon style that gave a %total speed penalty, but in return, a higher crit chance & a higher crit damage mod. You’d also later down the line get access to a Cleave skill, that only scales with main hand damage (& not off hand), & an altercation to the skill would cause two-handed weapons to fire off a shrapnel shell/bolt for the same effective aoe as the cleave once it hits a target (Like Ice Shot from Path of Exile).
For the DPS route, it would have a default attack replacer that started out with an attack speed penalty, but ramped up in attack speed to more than your base, similar to the way Shaman’s default attack replacer works, but for attack speed rather than %damage of weapon damage modified per hit. Once at full speed, melee attacks start to have a chance of cleaving up to 3 targets, & ranged attacks start to have a chance of piercing through to hit one extra enemy. Also, with ranged attacks, as you get faster, your gun/guns start to have a deviation left or right, making an effective cone of rapid-fire gun shots (kinda like a Gatling gun).
The Barbarian would also get some passively procing buffs, rewarding a high risk, high reward play-style. One giving a total speed & damage buff once you hit below 45% for a duration (Bloodrage), one making your crits have a chance to gib enemies so hard that they explode dealing damage to nearby enemies for the overkill damage (Total Carnage), & one that gives a %attack damage converted to health buff for maintaining a killstreak (Bloodlust)
A few of the active skills would be similar in regards to Warcries in PoE, such as a Warcry that taunts nearby mobs & gives you & allies in range of you beefed up defenses, or one that gives you & your allies extra damage in some way, like Enduring Cry or Rallying Cry. Also, a few other skills that are high damage weapon attacks, like the Cleave for two-handers, or a Dance of Blades for dual wield (Like PoE’s Cyclone), that spins for a duration while moving with decreased move speed & has an altercation that allows it to be used with guns to become like Reaper from Overwatch for a few seconds.
What do y’all think? :undecided: I’m not saying all these things that have to be in there, it’s just a general idea to start from. 